Struts基于List(未使用泛型)的类型转换

布满荆棘的人生 2021-07-24 11:37 383阅读 0赞

**一 视图**

1 input.jsp

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
    <%@taglib prefix="s" uri="/struts-tags"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title>直接封装成List</title>
    </head>
    <body>
    <h3>直接封装成List</h3>
    <s:form action="login">
        <s:textfield name="users[0].name" label="第一个用户名"/>
        <s:textfield name="users[0].pass" label="第一个密码"/>
        <s:textfield name="users[1].name" label="第二个用户名"/>
        <s:textfield name="users[1].pass" label="第二个密码"/>
        <tr>
            <td colspan="2"><s:submit value="转换" theme="simple"/>
            <s:reset value="重填" theme="simple"/></td>
        </tr>
    </s:form>
    </body>
    </html>

2 welcome.jsp

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
    <%@taglib prefix="s" uri="/struts-tags"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title>转换成功</title>
    </head>
    <body>
        <s:actionmessage/>
    第一个User实例的用户名为:<s:property value="users[0].name"/><br/>
    第一个User实例的密码为：<s:property value="users[0].pass"/><br/>
    第二个User实例的用户名为:<s:property value="users[1].name"/><br/>
    第二个User实例的密码为：<s:property value="users[1].pass"/><br/>
    </body>
    </html>

**二 配置文件**

<?xml version="1.0" encoding="GBK"?>
    <!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
        "http://struts.apache.org/dtds/struts-2.3.dtd">
    <struts>
        <package name="lee" extends="struts-default">
            <action name="login" class="org.crazyit.app.action.LoginAction">
                <result>/WEB-INF/content/welcome.jsp</result>
                <result name="error">/WEB-INF/content/welcome.jsp</result>
            </action>
            <action name="*">
                <result>/WEB-INF/content/{1}.jsp</result>        
            </action>
        </package>
    </struts>

**三 action**

package org.crazyit.app.action;
    
    import com.opensymphony.xwork2.ActionSupport;
    import java.util.List;
    
    import org.crazyit.app.domain.*;
    
    
    public class LoginAction extends ActionSupport
    {
        // Action类里包含一个不带泛型的List类型的成员变量
        private List users;
    
        // users的setter和getter方法
        public void setUsers(List users)
        {
            this.users = users;
        }
        public List getUsers()
        {
            return this.users;
        }
    
        public String execute() throws Exception
        {
            // 在控制台输出Struts 2封装产生的List对象
            System.out.println(getUsers());
            // 因为没有使用泛型，所以要进行强制类型转换
            User firstUser = (User)getUsers().get(0);
            // users属性的第一个User实例来决定控制逻辑
            if (firstUser.getName().equals("crazyit.org")
                && firstUser.getPass().equals("leegang") )
            {
                addActionMessage("登录成功！");
                return SUCCESS;
            }
            addActionMessage("登录失败！！");
            return ERROR;
        }
    }

对应的属性文件LoginAction-conversion.properties

Element_users=org.crazyit.app.domain.User

**四 领域模型**

package org.crazyit.app.domain;
    
    public class User
    {
        private String name;
        private String pass;
    
        // name的setter和getter方法
        public void setName(String name)
        {
            this.name = name;
        }
        public String getName()
        {
            return this.name;
        }
    
        // pass的setter和getter方法
        public void setPass(String pass)
        {
            this.pass = pass;
        }
        public String getPass()
        {
            return this.pass;
        }
    }

**五 测试**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 1][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70]: /images/20210724/9ac1fe04a17a4f54abcc1c6d5be8b3b9.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 1]: /images/20210724/8c895be81a294a63bee9737a8a9e8819.png